Inside the case is an Arduino and breadboard with three through-hole momentary buttons. These are wired up to the Arduino inputs and a sketch emulates keystrokes when connected to a computer.

The original keyboard for the VT220 is the LK201. This keyboard communicates with the terminal using 8-N-1 (eight data bits, no parity, one stop bit) over RS232 at 4800 baud.

But that’s not stopping DIY-er Penk Chen from building their own handheld PC called the Penkesu — a retro-futuristic ultraportable laptop with a mechanical keyboard.

The Bolt Industries Pico 87 is a fully customizable and programmable DIY mechanical keyboard kit that can be coded using the Arduino IDE.

To make that actually work, Robofun paired an Arduino board with some capacitive controllers for the base, and connected that to a Raspberry Pi that linked the keyboard to the TV.

DIY-er Penk Chen creates his own version of an ultra-portable handheld PC with a mechanical keyboard. Take a quick look at Penkesu.

DIY handheld PC uses mechanical keyboard, Game Boy pieces, Raspberry Pi Small number of electronic parts and a healthy amount of 3D printing.